A Short Cultural and Geological History of the Indian Heaven Plateau
A volcanic plateau in the Washington Cascades holds significance for both the Native Americans and geologists
Here’s a beautiful window seat view of Mt. St. Helens in the foreground and in the distance, Mount Adams (known as "Pahto" to the Yakama). I took this when flying to work this past Sunday.
In between Mount Adams and Mount St Helens is a volcanic plateau called the Indian Heaven Wilderness- the Native American name for the plateau is "Sahalee Tyee" which translates loosely into "Indian Heaven".
For thousands of years, the many tribes of the Cascades like the Yakama, Klickitat, Wasco, and even the Umatilla from eastern Oregon would meet on this plateau in the fall to trade, harvest wild berries and and hold important ceremonies. After horses were introduced to the Native Americans in the 1700s by the Spanish, the tribes of the Cascades would hold horse races here as an exhibition of their warriors' horsemanship- there is a meadow here called the Indian Racetrack where you can still see the tracks from those races.
The annual gatherings at Indian Heaven were more than just for subsistence and ceremony- they forged trade and cultural links amongst the many tribes present.
The Sawtooth Berry Fields are an especially rich area for wild berries long used by the tribes of the Pacific Northwest. From 1902 to the 1920s, the federal government restricted Native access to the fields which the Yakama Nation contested before an agreement was reached in 1932 between the Yakama and the US Forestry Service that set aside part of the area exclusively for the Native Americans, restoring an annual tradition that stretched back thousands of years.
Many of the hills and peaks of the Indian Heaven Wilderness are former volcanic cones and vents that formed this mountain plateau.
If you look at a map of the volcanoes of the High Cascades from Northern California to British Columbia, they all pretty much line up nicely....except Mount St Helens, which is about 20-30 miles west of where you’d expect it to be if it followed the trend of all the other Cascade volcanoes.
The Indian Heaven plateau between Mount Adams and Mount St Helens sits on a big giant slug of rock that was once part of an island archipelago that sat off the Pacific coast of North America millions years ago called Siletzia. Thanks to plate tectonics, that island arc got scraped up and slapped on the side of the North American continent. The proper geological term is “accreted”. What was once Siletzia was squeezed by millions of years of geological forces to form big wall of volcano-proof rock that funneled molten rock away from the line where most Cascade volcanoes form to a point west where Mount St. Helens now sits.
That research project was called iMUSH (imaging Magma Under St. Helens) and it just published its results last year.
While there are smaller volcanoes and lava vents all over Indian Heaven (there are about 50 eruption centers), none were big enough or long lasting enough to build a volcano the size of the other volcanoes of the High Cascades.